894f7a4ba6
Fix duplicated attributes on nonterminal expressions This PR fixes a long-standing bug (#86055) whereby expression attributes can be duplicated when expanded through declarative macros. First, consider how items are parsed in declarative macros: ``` Items: - parse_nonterminal - parse_item(ForceCollect::Yes) - parse_item_ - attrs = parse_outer_attributes - parse_item_common(attrs) - maybe_whole! - collect_tokens_trailing_token ``` The important thing is that the parsing of outer attributes is outside token collection, so the item's tokens don't include the attributes. This is how it's supposed to be. Now consider how expression are parsed in declarative macros: ``` Exprs: - parse_nonterminal - parse_expr_force_collect - collect_tokens_no_attrs - collect_tokens_trailing_token - parse_expr - parse_expr_res(None) - parse_expr_assoc_with - parse_expr_prefix - parse_or_use_outer_attributes - parse_expr_dot_or_call ``` The important thing is that the parsing of outer attributes is inside token collection, so the the expr's tokens do include the attributes, i.e. in `AttributesData::tokens`. This PR fixes the bug by rearranging expression parsing to that outer attribute parsing happens outside of token collection. This requires a number of small refactorings because expression parsing is somewhat complicated. While doing so the PR makes the code a bit cleaner and simpler, by eliminating `parse_or_use_outer_attributes` and `Option<AttrWrapper>` arguments (in favour of the simpler `parse_outer_attributes` and `AttrWrapper` arguments), and simplifying `LhsExpr`. r? `@petrochenkov`
UI Tests
This folder contains rustc's
UI tests.
Test Directives (Headers)
Typically, a UI test will have some test directives / headers which are special comments that tell compiletest how to build and intepret a test.
As part of an on-going effort to rewrite compiletest
(see https://github.com/rust-lang/compiler-team/issues/536), a major
change proposal to change legacy compiletest-style headers // <directive>
to ui_test-style headers
//@ <directive> was accepted (see
https://github.com/rust-lang/compiler-team/issues/512.
An example directive is ignore-test. In legacy compiletest style, the header
would be written as
// ignore-test
but in ui_test style, the header would be written as
//@ ignore-test
compiletest is changed to accept only //@ directives for UI tests
(currently), and will reject and report an error if it encounters any
comments // <content> that may be parsed as an legacy compiletest-style
test header. To fix this, you should migrate to the ui_test-style header
//@ <content>.